1. Field of the Invention
The present invention relates to a process for producing L-arginine by fermentation and strains of microorganisms which produce L-arginine in high yield.
2. Discussion of the Background
L-Arginine is an important component of drugs for stimulating liver functions, amino acid infusion, total amino acid preparations, etc. To reduce the production costs of L-arginine, it is important to improve the fermentation yield. In order for microorganisms belonging to the genus Brevibacterium or the genus Corynebacterium to exhibit L-arginine productivity, it is known that a resistance to 2-thiazolealanine (hereafter simply referred to as 2-TA), arginine hydroxamate, etc. should be imparted to the microorganism. It is also known that the production of L-arginine is improved by imparting sulfa agent or argininol resistance, resistance to chemicals such as 8-azaguanine, .alpha.-amino-.beta.-hydroxyvaleric acid, etc., in addition to the chemical resistance described above, and by imparting auxotrophy for amino acids such as L-histidine, L-proline, L-threonine, L-tryptophan, L-lysine, etc.
However, use of the conventional L-arginine-producing strains of microorganisms results in an unsatisfactory yield of L-arginine. Thus, there remains a need for a process for producing L-arginine by fermentation in high yield. There also remains a need for strains of microorganisms which produce L-arginine in high yield by fermentation.